lorry gets
through to its destination unchallenged, and the stuff is unloaded. The
manager arranges that the four kegs of brandy will disappear. He takes
over the certificate which does not show brandy, signs it, and the
transaction is complete. Everything is in order, and he has got four
kegs smuggled in."

"Good," Willis interjected.

"On the other hand, suppose the one o'clock trip is held up by an
exciseman. This time Fox produces the other certificate, the one which
shows the brandy. Once again everything is in order, and the Excise
officer satisfied. It is true that on this occasion Fox has been unable
to smuggle out his brandy, and on that which he carries duty must be
paid, but this rare contingency will not matter to him as long as his
method of fraud remains concealed."

"Seems very sound so far."

"I think so. Let us now consider the four o'clock trip. Fox arrives back
at the works with one of the two certificates still in his pocket, and
the make up of his four o'clock load depends on which it is. He attempts
no more smuggling that day. If his remaining certificate shows brandy
he carries brandy, if not, he leaves it behind. In either case his
certificate is in order if an Excise officer holds him up. That is, when
he has at tended to one little point. He has to add two strokes to the
1 of the hour to make it into a 4. The ease of doing this explains why
these two hours were chosen. Is that all clear?"

"Clear, indeed, except for the one point of how the brandy item is added
to the correct block."

"Obviously Archer does that as soon as he learns how the first trip has
got on. If the brandy was smuggled out on the first trip, it means that
Fox is holding the brandy-bearing certificate for the second, and Archer
enters brandy on his second block. If, on the contrary, Fox has had his
first load examined, Archer will make his entry on the first block."

"The scheme," Willis declared, "really means this. If Archer wants to
smuggle out one hundred gallons of brandy, he has to send out another
hundred legitimately on the same day? If he can manage to send out two
hundred altogether then one hundred will be duty clear, but in any case
he must pay on one hundred?"

"That's right. It works out like that."

"It's a great scheme. The only weak point that I can see is that an
Excise officer who has held up one of the trips might visit the works
and look at the certificate block before Archer gets it altered."